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J. SNEED Tamb E3, 1931.-

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BRAKE Filed May 28,v 1928 ZSheets-Sheet l lcfrl J. SNEED BRAKE 2SheetS-Sheet 2 Filed May 28, 1928 rannte im. ia. resi UNrrEo sTTEs .naar

JOHN SNEED, F DETROIT, MICHIGAN, ASSIGNOE TG THE MIDLAN) STEEL PRODUCTSCOMPANY, A CORPORATION 0F OHIO 'BRAKE Application filed May 28, 1928.Serial No. 281,062.

e provide means for quickly and easily ,adjusting the size and positionof the shoe with regard lto the brake drum. Another object is to adjustthe elect'ive length of the shoe. A further object is to provideadjusting means by which the several brakes in a given vehicle can bequickly and accurately adjusted with enact likeness to the sameoperative relation to the several drums and other functionally relatedbrake parts. A further object is to provide simple and e'ective meansfor adjustably and resiliently centering thel unancliored parts of thebrake shoe so that uniform clearance may be maintained as the shoe isadjusted and displaced to compensate for wear.

@ther objects will appear from the followf ing description of apreferred form of my in-l vention which is shown in the environment et awell known brake of the internal expanding type. A preferred form of myinvention is illustrated in the drawings; the essential characteristicsare summarized in the claims.

In the drawings, Fig. l is an elevation of the brake assembly includingthe shoe within the drum; Fig. 2 is a vertical section through the upperpart of the assembly illustrated in lFig. l; Fig. 3 is a section takenalong the line 3 3 et Fig. 2; Fig. t is a section taken alongthe linelf-4 of Fig. 2; Fig. 5 is a perspective ot the adjustor retainin memberwhich is secured to one end of the s oe; Fig. 6 is a section taken alongthe broken line 6 6 ot Fig. l.

Referring particularly to Fig. l, the brake assembly consists of a backplate or apron A which carries an anchor pin P and is secured to arelatively xed part et the vehicle. Brake drum D is secured to .theWheelv and revolves in the usual manner. rlihe friction elementillustrated comprises a substantially annular shoe S carrying the usualbrake lining L. The shoe S is oit the full floating type and comprises arelatively rigid channel part l .and a relatively flexible band part 2which may be joined together by a butt weld 3. The channeled end of theshoe engages the anchor pin P along the arcuate bearing portions 4 andto the-other end of thev shoe is adjustably secured a member 10 Whichengages the anchor pin along the arcuate bearing surfaces 5. To operatethe brake, spreading mechanism in the form of a toggle T which is wellknown 1n' this type of brake construction has its ends connected to thechanneled end of the shoe and to the piece 10. The pivot pin 6 of thetoggle may be drawn toward the apron to expand the brake by such meansas a cable or floating link, not shown. Brakes are arranged in thevehicle so that the forward movement of the Vehicle causes drum rota.-

tion as indicated by the arrow and in the usual operation of retardingthe vehicle, the

:member 10 is moved from the anchor carrying the free end of the bandpart of the shoe into engagement with the drum and swinging the lessflexible part of the shoe 1 about the anchor into engagement, thebraking torque being taken through the side flanges of the rchannelalong the anchor engaging surfaces d.

'lRetractor springs 7 and 8 may be fixed to the apron at adjacent endsand secured to the ends of the shoes to draw these ends against theanchor. The spring 7 may exert a slightly greater tension so that in theusual operation the dexible part of the shoe will be moved from theanchor into engagement with the drum. Centering springs 30 and. 31position the bottom or mid-portion of thev shoe in its idle position andare adjustably secured to the apron in a manner to be descrihedbelow.

Referrin also to` Figs. 2 to 5 inclusive; l will descri e particularlythe means `for adjusting and changing the total eil'ective length of theshoe. As mentioned above, the

member 10 is adjustably connected to the end of the band-like portion 2et the shoe.v As the member l0 is moved away from this part of the shoe,the total edective length of the shoe is increased. The member l() inaddition to having the arcuate bearing portions 5 also has dependingears ll, see also,l Fig. l, which carry a pin for engaging the toggleand l length of the shoe.

has a tail part or piece 12 which is curved and engages the inner sideof the band-like portionofthe shoe along theextended area as at 13, seealso Figs. 3 and 4. The tail piece 12 extends into a drawn cupped member15, see Figs. 1 and 5, which is secured near the end of the band portionof the shoe by such means as rivets. As shown in Figs. 3 and 4, the tailpiece 12 is closely engaged by the wall and bottom of the member 15.

Within the member 15 and bearing against its closed end, as at 16, is acoil spring 17 which lies within a cut away part of the tail piece andbears against it as at 18. The spring is held compressed and tends toforce the tail piece and the member 10 out of the retaining member 15 toincrease the total eiiectivlei Thus without other means to prevent it,the spring 17 would force the shoe into engagement with the drum.

'1 o hold the adjusting member 10 in a given position with relation tothe end of the shoe, the bottom of the cupped retaining member 15 isslotted as at 19, so that at 'ieast part of its walls may be drawn`together to clamp the tail piece 12 between them as shown in Fig. Thetail piece 12 is slotted as at 20. A bolt 21, see Figs. 1, 2 and 4i,clamps the tail piece in any desired position. 'lo effect adjustment,the boit 21 is released so that the spring 17 may extend the length ofthe shoe, then the toggle '1 is flattened a desired amount to 'force theadjusting member and the tail piece clockwise, as viewed in Figs. 1

and 2. rFhereupon the tail piece is clamped between the weils or@ themember 15, and asthe toggle is released the member 10 is drawn baclr onthe anchor and the shoe then clears the dr m by a desired amount. rEheend of the bo t 21 may be slotted as at 22 so that adj ustment may beeected by the nut 23 through an aperture in the apron 25. A cover 26 forthe aperture may be provided as shown in Fig. 4i. 4

ln making the adjustment described in the foregoing paragraph it will beseen that the mid-portion of the brake shoe adjacent the welded `ioint 3is moved clockwise as viewed in Fig. 1 when the total effective lengthof the shoe is increased. Under such a circumstance, the spring 30 wouldbe under greater tension than the spring 31, see 1 and 6, with theresult that a greater clearance would be had adjacent the part 1 of theshoe than the part 2 of the shoe. To compensate for this, the adjacentends of the springs 30 and 31 are secured to a member32 which may beadjustably positioned with regard to the apron. A bolt 33 carries themember 32 and passes througha slot Stein the apron so that the member 32may be shifted as viewed in Fir'. 1 and adjustably secured in anydesired position by the bolt 33. The springs 30 and 31 are secured'attheir far ends to the shoe and entend at an angle to the apron and drawmesser the shoe toward the apron against indented portions d() in theapron, see Figs. 1 and 6. ln this manner the-mid-portion oi the shoe iscentered and the Whole shoe is held out of Contact with the drum in idleposition. The edge of the shoe is drawn against the indents 40 in theapron. The indents 40 are spaced apart so that the shoe is held againstoscillating about a vertical axis and rattling in idle position. Thebolt 33 is spaced below a chord which joins the remote ends of thesprings both to give the springs better mechanicai advantage incentering the shoe and to exert forces more nearl to the curvature ofthe shoe so that the springs 30 and 31 will not tend to raise or lowerthe shoe from the anchor.

rEhe foregoing is a description of a preerred form o1' my invention.lhile modifications within its scope will occur to those skilled in theart, 1 do not care to be limited other than by the claims appendedhereto.

l claim 1. brake shoe having a thrust member at one end, and a springacting between the shoe said member and tending to torce the memberbeyond the end of the shoe.

2. fi. brake shoe having a thrust member adjustabiy secured thereto,means urging said member for movement relative to said shoeand means forclamping said member in hired position.

3. The combination of a brake shoe, a separate thrust member associatedwith the shoe, a normaiiy compressed spring acting between the memberand the shoe and means for heidlnng said member and said shoe inreiatively nxed position against the force said spring.

The combination of a .friction device. a thrust member at one endthereof, a normally compressed spring acting between the inember and theshoe and means for holding said member and said shoe in relatively iixedposition against the `force ofi said spring.

5. lin brake, the combination or an expending device, e. shoe, aseparate 'thrust member associated with the end` of the shoe andengaging said expanding device, and a normaliy compressed spring actingbetween said member and said shoe.

6. l'n a brake, the combination of an anchor, a shoe anchorabie at icastat one end, a separate thrust member associated with the' end ofthe shoeand engaging the anchor, and a normally compressed spring acting betweensaid member and said shoe and tending to :torce the shoe away from theanchor.

7. 1n a brake, the combination of a shoe,'a member adjustably secured tothe end of the shoe, means engaging said member for forcing the shoeagainst the drum, said member being positionable with relation to theshoe -by the pressure exerted by said means when the shoe is forced intoengagement with the 18. In a brake, the combination of a revolving drum,an apron, an anchor carried by the apron, a substantially annular fulloating shoe anchorable at either end, a separate member at one end ofthe shoe adjustably positioned with relation thereto and engaging theanchor, means for centering the portion of the shoe remote from theanchor and for maintaining clearance between the shoe and the drum whenthe brake is idle comprisingr a plate adjustably secured to the apron,and a pair of coil springs having their near ends connected to saidplate and their far ends connected to the shoe at spaced points.

19. In a brake, the combination of a re; volving drum, an apron, ananchor carried by the apron, a substantially annular full floating shoehaving both ends pivotally supported by the anchor when the brake 'isidle, and means for centering the portion of the shoe remote from theanchor and for maintaining clearance between the shoe and the drum whenthe brake is idle comprising a plate adjusably secured to the apron, anda pair of coil springs having their near ends connected to said plateand their far ends connected to the shoe at spaced points and beingdisposed at an angle to the plane of the apron, said apron having raisedportions near the points of attachment between said spring and said shoewhereby the edges of the shoe are resiliently urged against said raisedportion and whereby the mid-portion of the shoe is resilient-ly urged toan idle position determined by the position of said plate with relationto said apron.

ln testimony whereof, l hereunto affix rny signature.

JOHN SNEED.

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